Sthanu Ravi Varma (early Malayalam and Tamil: Ko Tanu Iravi), known as the Kulasekhara, was the Chera Perumal ruler of Kerala in southern India from 844/45 to c. 870/71 AD. He is the earliest medieval Chera ruler of Kerala known to scholars. Sthanu Ravi notably assisted the Chola ruler Aditya I (c. 871âÂÂ907 AD) in conquering the Kongu country from the Pandyas around 885 AD.
The famous Quilon Syrian Christian copper plates are dated to the fifth regnal year of king Sthanu Ravi. Two more inscriptions dated in the regnal years of Sthanu Ravi are found at the Irinjalakuda Kudalmanikyam Temple and at Thiruvatruvay, Thiruvalla. The Koyil Adhikarikal ("Royal Prince") during his time was his son-in-law (husband of his daughter), Vijayaraga. Sthanu Ravi had a son born around 870 AD. He was succeeded by Rama Rajasekhara (c. 870/71âÂÂc. 883/84).
Toward the end of his reign, Sthanu Ravi probably abdicated the throne and became a Vaishnavite alvar saint known as Kulasekhara Alvar (the seventh of the twelve mystic alvars). He is also identified with the playwright Chera king "Kulasekhara Varma".
Sthanu Ravi Kulasekhara is regarded as the earliest known Chera ruler (the Perumal) of Kerala. It is speculated that present-day central Kerala likely separated from the larger Chera or Kerala kingdom around the 8thâÂÂ9th century AD to form the Chera kingdom of Mahodayapuram-Kodungallur. Central Kerala was probably under some form of viceregal rule before this period.
The direct sovereign authority of the Chera Perumal king was likely restricted to the country around the capital, Makotai (Mahodayapuram, present-day Kodungallur), in central Kerala. His pan-Kerala kingship was likely ritualistic, remaining nominal compared to the political and military power wielded by local chieftains (the udaiyavar). Nambudiri Brahmins also exercised significant authority in religious and social matters, a system often described as "ritual sovereignty combined with Brahmin oligarchy".
Sthanu Ravi appears to have acted as a junior ally in a military campaign led by the Chola ruler bearing the title "Rajakesari Varma" in the Kongu country (central Tamil Nadu). Epigraphic evidence indicates that the two rulers jointly conferred military honours upon a Tanjore chief named Vikki Annan, who was married to a woman identified as "Kadamba Mahadevi". Vikki Annan was likely a Ganga prince, being the son of Prithvipati, and is mentioned in a Ganga inscription dated to the mid-9th century AD. The designation "Kadamba" in the princess's name suggests a probable affiliation with the Kadamba lineage.
The identity of the Chola ruler titled "Rajakesari Varma" remains a subject of scholarly debate. One interpretation, advanced by historian Elamkulam P. N. Kunjan Pillai, identifies "Rajakesari Varma" with Aditya Chola (c. 871âÂÂ907 AD). This hypothesis assumes that Sthanu Ravi ruled Kerala until around 885 AD, enabling his participation as a junior partner in Aditya CholaâÂÂs Kongu campaigns, particularly the conquest of the region from the Pandyas (c. 885 AD). Recent scholarship generally supports this view. An alternative interpretation, accepted by M. G. S. Narayanan (1972/1996) following T. V. Mahalingam ("An Interregnum in Pallava History", JIH, XLI, I), identifies "Rajakesari Varma" with Srikantha Chola (817âÂÂ845 AD), thereby placing the joint military action in Kongu around 844/45 AD.
The astronomer and mathematician Sankaranarayana (c. 840âÂÂ900 AD) served as a distinguished member of the royal court of Kulasekhara at the capital, Mahodayapuram (present-day Kodungallur). He is best known for authoring the Laghubhaskariyavyakha, an extensive commentary on the works of the eminent mathematician Bhaskara I (7th century AD). Evidence suggests that an "astronomical observatory" operated at Mahodayapuram under Sankaranarayana's supervision.
The vyakhya contains references to an instrument termed the "Rashichakra", marked by a "Yanthravalaya". This "device" is possibly identical to the Golayanthra or Chakrayanthra described by the renowned polymath Aryabhata. The Chakrayanthra was subsequently refined and came to be known as the Phalakayanthra by Bhaskara I.
Ayyan Adikal, the chieftain of the port of Quilon (present-day Kollam) under Sthanu Ravi, issued the renowned Quilon Syrian Christian copper plates around 849 AD. The inscription records that Ayyan Adikal granted land and serfs to a Christian church at Quilon, established by Mar Sapir Iso, and entrusted its maintenance to the trade guilds anjuvannam and manigramam. The grant was made in the presence of the Chera Perumal prince Vijayaraga. An inscription from Kanyakumari indicates that Vijayaraga was married to a daughter of Kulasekhara, titled Kizhan Adikal Ravi Neeli, and was likely the son of Kulasekhara's sister.
In his commentary Laghubhaskariyavyakha, Sankaranarayana notes that he was patronized by a king of Mahodayapuram named "Ravi", who bore the title "Kulasekhara", thereby supporting the identification of Sthanu Ravi with Kulasekhara. The opening verse of the commentary also contains an indirect invocation to a lord referred to as "Sthanu", deliberately composed so as to be applicable both to the deity Shiva and to the reigning monarch.
Laghubhaskariyavyakha also provides two distinct dates, one in the Kali Era (866 AD, the date of an eclipse) and the other in the Saka Era (870 AD).
According to its own testimony, the Laghubhaskariyavivarana was composed in the 25th regnal year of Ravi Kulasekhara (869/70 AD), placing his coronation around 844/45 AD.
Further, Sankaranarayana mentions the conjunction of Guru (Jupiter) and Sauri (Saturn) in Capa (Dhanu), stating that it occurred when the king had completed 25 regnal years (Chapter VII). It is known that, in the 9th century AD, Jupiter and Saturn simultaneously entered Dhanu Rasi only in 869 AD.